Embodiments of the present inventive concept relate to a method of operating a central processing unit (CPU), and more particularly to the method of operating a CPU capable of adjusting a quality of service (QoS) of the CPU, and a method of operating a system including the CPU.
A microprocessor, particularly, a mobile application processor uses a technology of dynamically changing an operating frequency, for example, a dynamic frequency scaling (DFS) technology or a dynamic voltage and frequency scaling (DVFS) technology, to satisfy demands in both performance and low power. The microprocessor uses various policies for adjusting a frequency of an operating clock signal. A mobile environment may impose a limit on the amount of power to be used and may create vulnerability to heat, and thus the policies constrain performance of a microprocessor, and the microprocessor is designed to minimize power consumption and heat generation.
A DVFS governor of the DVFS used in a microprocessor of the prior art is optimized for limiting the power consumed in the microprocessor, such that an operating frequency of the microprocessor is not immediately increased to a maximum operating frequency even if a certain task continuously uses the maximum available performance of the microprocessor.